If you've ever fancied yourself as a Hollywood screenwriter, producer or even star, the film section of crowdfunding site IndieGoGo might just be the place for you. Browse through the fledgling movie projects touting for cash in the past few months, and you might have come upon opportunities to pick up a writer's credit for $50 on the British post-apocalyptic drama Remnants of a Disaster, or an executive producer's credit on the Kiwi documentary God Is Incredible for $500. The director of comic book tale Super Day recently promised to shave his head if the film's campaign reached its $3,500 target, with donors permitted to scribble their names on his newly bald pate.

Amid the silliness, the site addresses a very real need. Movies cost an awful lot of money to make, and not everybody who wants to make movies has an awful lot of money. Some of these features may provide the opportunity for the next Kevin Smith or David Lynch to take their first step on the film-making ladder. And yet one cannot quite imagine either of the above offering to pass over creative duties on Clerks or Eraserhead for less than the cost of dinner for two at a half decent curry house, as at least one IndieGoGo project has promised recently.

A shift in terminology may even be in order: crowdfunding, via which film-makers reach out for help with the financial costs of a particular project, is becoming increasingly blurred with crowdsourcing, via which wannabe producers engage fans via the internet to become part of the creative process of putting together a new movie. Kept separate, each has its place. When one becomes contingent upon the other, creating a sort of "crowdeverything" hybrid, it gives the film projects in question an unsavoury air of mercantile desperation.

"There is a real dark side emerging," says British independent film producer and screenwriter Ant Neely. "I am seeing crowdfunding campaigns that offer 'a line in the film and an IMDb credit' for a big enough donation. The thought of casting someone because they can pay, as opposed to their abilities, is really very sad."

Neely and his wife Sloane U'Ren (a director) took a different approach to getting their science fiction-cum-period drama flick Dimensions: A Line, A Loop, A Tangle of Threads, on to the big screen – they simply sold their house. While he accepts that getting a movie financed is an incredibly difficult process, Neely doesn't believe the crowdeverything approach is the way forward.

"It's an interesting concept and arguably connects a film-maker directly with the audience," he says. "However, we're not comfortable with having movies made by committee. I'm not saying selling your home is any more of a sensible strategy though!"

If one film has a chance of escaping the crowdsourcing/funding ghetto, it's Iron Sky, a comedy romp about space Nazis from Finnish director Timo Vuorensola and a supporting online crew of thousands which is released on Wednesday in UK cinemas (more of which later). The €7.5m film will be shown in more than 70 countries this year and stands a good chance of making a profit for its legions of financial backers. Despite its origins, Vuorensola says his film eschewed the cash-for-credits approach.

"I have to say that I've been seeing this kind of thing a lot," he says. "They always start out cool and everybody is really excited for two weeks but then there's a mess of everybody doing something. If you want to crowdsource you have to be very dominant – I've always made it clear with Iron Sky that this is not a democracy, this is a dictatorship.

"With our film the idea was to use the community to develop ideas and issues that are problematic rather than get them working on the script. We needed lyrics for the national anthem of the moon Nazis, and I don't speak German, so it was something we put to the community. They knew what I was looking for, and they were able to let me know if something that someone had written was getting close."

Since this interview was conducted, it has emerged that the Iron Sky is to be released for just one day in the UK, a decision which producers have blamed on the distributor, Revolver. "The fact that they are releasing Iron Sky for just one day (in the middle of the week) shows a great disrespect for us, the film-makers, who have been slaving to make this film as cinematic – with big special effects, sounds and great action – as possible," reads a statement on the movie's website. "It's also a major middle finger to the fans, followers and investors who have been following the production for years and now suddenly have only a few hours to run to the theatre, and then enjoy their quickly rushed DVD and Blu-ray release."

Might the decision be linked to lukewarm early reviews for the film? And does the critical indifference which has greeted the project emanate from its crowdsourced origins? If so, the Iron Sky team are showing no sign of having got the message: their statement asks fans to email Revolver in protest at the short UK run. There's something to be admired, at the very least, in the producers' determination and audacious, barefaced belief in people power. Shouldn't critics take account of the film's meagre budget and reward its struggle in the face of adversity, rather than gloat over its failures?

He adds: "Cinema going back to (Robert Rodriguez's) El Mariachi has benefited from people reviewing the budget. Critics are supposed to be detached, but you tend to absorb the conditions under which the work is made. However in the case of Iron Sky the special effects were great, but after the first five minutes it really fell apart.

"The wider story is that 95% of filmmakers can't get the money they want, and crowdfunding is the latest thing. It was the same a few years back with microbudget and people like Terence Davies doing films for pennies: the first few who get on the bandwagon have done well but then you get the lemming-like rush. I find the thought of people surrendering control over their film – to treat it like it's a commodity – very bizarre. Giving someone a role as an extra is one thing, but writing is a very difficult art. It's like selling off articles in newspapers."

• Iron Sky is released in UK cinemas on Wednesday. Dimensions: A Line, A Loop, A Tangle of Threads was shown recently at the London film festival, and also at the London independent film festival, where it won best film.